Basic Java Program

Basic Java Program

This is a simple program that prints Hello World on screen. Most programmers write the Hello World program as their first program.

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello World");
    }
}

Hello World

Basic Java Program Explained

• Every code that runs in Java must be inside a class.
• A class should always start with an uppercase first letter.
• The name of the java file must match the class name.
• public static void main(String[] args) means main function. Our program starts with main function.
• System.out.println(“Hello World”); prints Hello World on Screen.
• The curly braces {} mark the beginning and the end of a block of code.
• Each code statement must end with a semicolon.

Work 1: Write a program to print your name in Java.

Java Program For Basic Calculation

This program performs basic calculation like addition, subtraction, multiplication, and division.

public class Main {
    public static void main(String[] args) {
        System.out.println("This is my first java program");
        int num1 = 10;
        int num2 = 20;

        int sum = num1 + num2;
        int diff = num1- num2;
        int mul = num1 * num2;
        int div = num1 / num2;

        System.out.println("The sum is "+sum);
        System.out.println("The diff "+diff);
        System.out.println("The mul is "+mul);
        System.out.println("The div is "+div);
    }
}

This is my first java program
The sum is 30
The diff -10
The mul is 200
The div is 0

Points To Remember

• You don’t need the double quotes to output numbers.
• System.out.println() prints the output on the screen.
• In Java, each statement must end with a semicolon.

Challenge

• Create a java program to print sum of three numbers.